scholarly journals The effect of additives on the properties of electrodeposited Ni–zircon composite coatings

RSC Advances ◽  
2016 ◽  
Vol 6 (14) ◽  
pp. 11185-11192 ◽  
Author(s):  
S. T. Aruna ◽  
P. G. Lashmi ◽  
H. M. Seema
Keyword(s):  
Composite Coating ◽  
Composite Coatings ◽  
Effect Of Additives ◽  
Zircon Powder

In the present study, the suitability of zircon powder as a new distributive phase for electrodeposited Ni composite coating is explored.

scholarly journals Influence of Pulse Current Forward-Reverse Duty Cycle on Structure and Performance of Electroplated W–Cu Composite Coatings

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1233
Author(s):  
Yuchao Zhao ◽  
Nan Ye ◽  
Haiou Zhuo ◽  
Chaolong Wei ◽  
Weiwei Zhou ◽  
...  
Keyword(s):  
Composite Coating ◽  
Duty Cycle ◽  
Electrode Materials ◽  
Pulse Current ◽  
Electrical Discharge Machining ◽  
Composite Coatings ◽  
Electrical Contact ◽  
Pulse Plating ◽  
Fusion Welding ◽  
Raw Material

Tungsten-copper (W–Cu) composites are widely used as electrical contact materials, resistance welding, electrical discharge machining (EDM), and plasma electrode materials due to their excellent arc erosion resistance, fusion welding resistance, high strength, and superior hardness. However, the traditional preparation methods pay little attention to the compactness and microstructural uniformity of W–Cu composites. Herein, W–Cu composite coatings are prepared by pulse electroplating using nano-W powder as raw material and the influence of forward-reverse duty cycle of pulse current on the structure and mechanical properties is systematically investigated. Moreover, the densification mechanism of the W–Cu composite coating is analyzed from the viewpoints of forward-pulse plating and reverse-pulse plating. At the current density (J) of 2 A/dm2, frequency (f) of 1500 Hz, forward duty cycle (df) of 40% and reverse duty cycle (dr) of 10%, the W–Cu composite coating rendered a uniform microstructure and compact structure, resulting in a hardness of 127 HV and electrical conductivity of 53.7 MS/m.

scholarly journals Preparation and Degradation Characteristics of MAO/APS Composite Bio-Coating in Simulated Body Fluid

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 667
Author(s):  
Zexin Wang ◽  
Fei Ye ◽  
Liangyu Chen ◽  
Weigang Lv ◽  
Zhengyi Zhang ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Composite Coating ◽  
Body Fluid ◽  
Composite Coatings ◽  
Degradation Process ◽  
Ceramic Coatings ◽  
Immersion Test ◽  
Substrate Material ◽  
Atmospheric Plasma

In this work, ZK60 magnesium alloy was employed as a substrate material to produce ceramic coatings, containing Ca and P, by micro-arc oxidation (MAO). Atmospheric plasma spraying (APS) was used to prepare the hydroxyapatite layer (HA) on the MAO coating to obtain a composite coating for better biological activity. The coatings were examined by various means including an X-ray diffractometer, a scanning electron microscope and an energy spectrometer. Meanwhile, an electrochemical examination, immersion test and tensile test were used to evaluate the in vitro performance of the composite coatings. The results showed that the composite coating has a better corrosion resistance. In addition, this work proposed a degradation model of the composite coating in the simulated body fluid immersion test. This model explains the degradation process of the MAO/APS coating in SBF.

scholarly journals Isothermal Oxidation Performance of Laser Cladding Assisted with Preheat (LCAP) Tribaloy T-800 Composite Coatings Deposited on EN8

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 843
Author(s):  
Sipiwe Trinity Nyadongo ◽  
Sisa Lesley Pityana ◽  
Eyitayo Olatunde Olakanmi
Keyword(s):  
Iron Oxide ◽  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Parabolic Rate Constant ◽  
Mass Gain ◽  
Isothermal Oxidation ◽  
Operational Parameters ◽  
Temperature Oxidation ◽  
Service Environments

It is anticipated that laser cladding assisted with preheat (LCAP)-deposited Tribaloy (T-800) composite coatings enhances resistance to structural degradation upon exposure to elevated-temperature oxidation service environments. The oxidation kinetics of LCAP T-800 composite coatings deposited on EN8 substrate and its mechanisms have not been explored in severe conditions that are similar to operational parameters. The isothermal oxidation behaviour of the T-800 composite coating deposited on EN8 via LCAP was studied at 800 °C in air for up to 120 h (5 × 24 h cycles) and contrasted to that of uncoated samples. The mass gain per unit area of the coating was eight times less than that of the uncoated EN8 substrate. The parabolic rate constant (Kp) for EN8 was 6.72 × 10−12 g2·cm−4·s−1, whilst that for the T-800 composite coating was 8.1 × 10−13 g2·cm−4·s−1. This was attributed to a stable chromium oxide (Cr2O3) layer that formed on the coating surface, thereby preventing further oxidation, whilst the iron oxide film that formed on the EN8 substrate allowed the permeation of the oxygen ions into the oxide. The iron oxide (Fe2O3) film that developed on EN8 spalled, as evidenced by the cracking of oxide when the oxidation time was greater than 72 h, whilst the Cr2O3 film maintained its integrity up to 120 h. A parabolic law was observed by the T-800 composite coating, whilst a paralinear law was reported for EN8 at 800 °C up to 120 h. This coating can be used in turbine parts where temperatures are <800 °C.

The Deposition of Ni/Cr-Cr3C2 Composite Coatings by Arc-EB Hybrid Technology

2011 ◽  
Vol 674 ◽  
pp. 71-80 ◽  
Author(s):  
Jerzy Smolik ◽  
Adam Mazurkiewicz
Keyword(s):  
Electron Beam ◽  
Composite Coating ◽  
Arc Discharge ◽  
Composite Coatings ◽  
Chemical Compositions ◽  
Multilayer Composite ◽  
Substrate Bias Voltage ◽  
Hybrid Technology ◽  
Developed Surface ◽  
The Creation

The new hybrid technology is a combination of electron beam evaporation and arcevaporation processes, enabling the creation of the anti-erosion multilayer composite coating Ni/Cr- Cr3C2 with different volume of Cr3C2 filling in soft Ni/Cr matrix. The soft matrix made of Ni/Cr alloy and hard filling of Cr3C2 are created at the same time and directly during the electron beam and arc-evaporation process. Changes of the parameters of the hybrid process, i.e. pressure, current of arc discharge and substrate bias voltage Ubias, make it possible to control the volume of Cr3C2 and are a factor in filling the soft Cr/Ni matrix with carbides Cr3C2. With the use of the developed surface treatment hybrid technology, the multilayer composite coating Ni/Cr-Cr3C2 were obtained. For all composite layers created, the material properties, such as morphology, phase and chemical compositions, hardness, and Young modulus were investigated. The paper presents the original technological equipment, methodology, and technological parameters for the creation of the composite coating Ni/Cr-Cr3C2.

Experimental investigation of electrodeposited Ni-Al2O3/ZrO2 nano composite on HSLA ASTM A860 alloy

2021 ◽  
Author(s):  
Chandrasekhara Sastry Chebiyyam ◽  
Pradeep N ◽  
Shaik AM ◽  
Hafeezur Rahman A ◽  
Sandeep Patil
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Composite Coating ◽  
Base Alloy ◽  
Composite Coatings ◽  
Nano Particles ◽  
Alloy Sample ◽  
Nano Composite ◽  
Nano Coating ◽  
Nano Composite Coating

Abstract Nano composite coatings on HSLA ASTM A860 alloy, adds to the barrier efficacy by increase in the microhardness, wear and corrosion resistance of the substrate material. Additionally, reduction of delamination of the nano composite coating sample is ascertained. Ball milling is availed to curtail the coating samples (Al2O3/ZrO2) to nano size, for forming a electrodeposited product on the substrate layer. The curtailment in grain size was ascertained to be 17.62% in Ni-Al2O3/ZrO2 nano composite coating. During the deposition process, due to the presence of Al2O3/ZrO2 nano particles an increase in cathode efficiency is ascertained. An XRD analysis of the nano composite coating indicates a curtailment in grain size along with increase in the nucleation sites causing a surge in the growth of nano coating layer. In correlation to uncoated HSLA ASTM A36 alloy sample, a surge in compressive residual stress by 47.14%, reduction of waviness by 32.14% (AFM analysis), upsurge in microhardness by 67.77% is ascertained in Ni-Al2O3/ZrO2 nano composite coating. Furthermore, in nano coated Ni-Al2O3/ZrO2 composite a reduction is observed pertaining to weight loss and friction coefficients by 27.44% and 13% in correlation to plain uncoated alloy respectively. A morphology analysis after nano coating indicates, Ni-Al2O3/ZrO2 particles occupy the areas of micro holes, reducing the wide gaps and crevice points inside the matrix of the substrate, enacting as a physical barrier to upsurge the corrosion resistance by 67.72% in correlation to HSLA ASTM A860 base alloy.

About Determing the Microhardness of Composite Coatings

2021 ◽  
Vol 1037 ◽  
pp. 486-493
Author(s):  
Sergey Y. Zhachkin ◽  
Anatoly I. Zavrazhnov ◽  
Nikita A. Penkov ◽  
George V. Kudryavtsev ◽  
Paul V. Tsisarenko
Keyword(s):  
Composite Coating ◽  
Mechanical Treatment ◽  
Composite Coatings ◽  
Operational Parameters ◽  
Deposition Parameters ◽  
Cylinder Liners ◽  
High Degree ◽  
Applied Coating ◽  
Positive Effect ◽  
Selection Of

One of the fundamental tasks in restoring the operability of cylinder liners is the application of a composite coating with a predetermined microhardness value. The authors have developed a technology for applying composite coatings based on iron on cylindrical surfaces, which makes it possible to vary the physical, mechanical and operational parameters of the formed iron-containing coating due to the planned selection of the deposition parameters. This eliminates the need for mechanical treatment of the applied coating, which is the reason for the high degree of rejection parts that undergo the iron-on operation. Contact interaction of the working tool with the formed layer of the composite coating has a positive effect on the value of its roughness.

Microstructural characteristics of SiC-B4C reinforced laser alloying composite coatings

2013 ◽  
Vol 20 (4) ◽  
pp. 307-310
Author(s):  
Li Wei
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Fine Particles ◽  
Composite Coatings ◽  
Substrate Surface ◽  
Laser Alloying ◽  
Wear Process ◽  
High Microhardness ◽  
Deep Plowing ◽  
Coating Matrix

AbstractA hard SiC-B4C reinforced composite coating was fabricated by laser alloying of SiC-B4C+Al-Sn-Mo-Y2O3 mixed powders on a Ti-3Al-2V alloy. Al-Sn-Mo mixed powders were first used in the laser alloying technique to improve the wear resistance of titanium alloys. Proper selection of the laser alloying process parameters allows us to obtain a composite coating with a metallurgical combination with substrate. Under the action of Mo, fine particles with high microhardness were produced in the coating matrix and also hindered the formation of adhesion patches and deep plowing grooves during the sliding wear process, leading to the improvement of wear resistance of a titanium alloy substrate surface.

scholarly journals Influence of Polyurea Composite Coating on Selected Mechanical Properties of AISI 304 Steel

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3137 ◽  
Author(s):  
Monika Duda ◽  
Joanna Pach ◽  
Grzegorz Lesiuk
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Composite Coating ◽  
Composite Coatings ◽  
Glass Fabric ◽  
Coated Sample ◽  
Hemp Fiber ◽  
Aisi 304 ◽  
Aisi 304 Steel ◽  
The Impact

This paper contains experimental results of mechanical testing of the AISI 304 steel with composite coatings. The main goal was to investigate the impact of the applied polyurea composite coating on selected mechanical properties: Adhesion, impact resistance, static behavior, and, finally, fatigue lifetime of notched specimens. In the paper the following configurations of coatings were tested: EP (epoxy resin), EP_GF (epoxy resin + glass fabric), EP_GF_HF (epoxy resin + glass fabric hemp fiber), EP_PUA (epoxy resin + polyurea) resin, EP_GF_PUA (epoxy resin + glass fabric + polyurea) resin, and EP_GF_HF_PUA (epoxy resin + glass fabric + hemp fiber + polyurea) resin. The highest value of force required to break adhesive bonds was observed for the EP_PUA coating, the smallest for the single EP coating. A tendency of polyurea to increase the adhesion of the coating to the base was noticed. The largest area of delamination during the impact test was observed for the EP_GF_HF coating and the smallest for the EP-coated sample. In all tested samples, observed delamination damage during the pull-off test was located between the coating and the metallic base of the sample.

Study on the Wear Resistance of Micro-Nanostructured WC Composite Coating Sintered by Induced Heating

2007 ◽  
Vol 280-283 ◽  
pp. 1489-1492
Author(s):  
Zhen Ting Wang ◽  
Hua Hui Chen
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Solid Solutions ◽  
Composite Coatings ◽  
Micro Hardness ◽  
Q235 Steel ◽  
Metallurgical Bonding ◽  
Sintering Method

Micro-nanostructured WC composite coatings were successfully fabricated by induced heating sintering method on the surface of Q235 steel .The microstructure, micro-hardness and the wear resistance of the composite coatings were studied .The results show that the microstructure of induced heat layer is mainly composed of Ni-based solid solutions and WC particles. And there exists excellent metallurgical bonding between coating and substrate. The wear resistance of micro-nanostructured WC Composite Coatings is increased by 1.5 times on an average as compared with that of micron.

Fabrication of an Apatite/Collagen Composite Coating on the NiTi Shape Memory Alloy through Electrochemical Deposition and Coating Characterisation

2009 ◽  
Vol 618-619 ◽  
pp. 319-323 ◽  
Author(s):  
Parama Chakraborty Banerjee ◽  
Tao Sun ◽  
Jonathan H.W. Wong ◽  
Min Wang
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Composite Coating ◽  
Electrochemical Deposition ◽  
Room Temperature ◽  
Composite Coatings ◽  
Deposition Process ◽  
Niti Shape Memory Alloy ◽  
X Ray ◽  
Niti Sma

To improve the biocompatibility and bioactivity of NiTi shape memory alloy (SMA), apatite/collagen composite coatings were fabricated on the surface of NiTi SMA at room temperature using the electrochemical deposition technique. Spherical apatite particles and fibrous collagen that formed the composite coating were visible under scanning electron microscope (SEM). The Ca/P ratio of the apatite component in the coating, as determined by energy dispersive X-ray spectroscopy (EDX), was about 1.38 which is slightly higher than that of octocalcium phosphate (OCP). X-ray diffraction result showed that the apatite was amorphous, which was due to the low temperature (i.e., room temperature) deposition process. The structure of the composite coatings was further characterized using Fourier transform infrared reflection spectroscopy (FTIR). It was also found that, compared to bare NiTi SMA samples, the wettability of as-deposited samples was increased because of the formation of the composite coating.

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